Pressing device for toroidal continuously variable transmission

Abstract

Provided is a pressing device for toroidal continuously variable transmission capable of reducing hysteresis that occurs between torque and pressing force. An intermediate sliding member 27 is provided in at least one location of a portion between an end surface on the outside in the radial direction of the retainer 13 of the roller 14 arranged on the outermost side in the radial direction and an inside surface of the pocket 25 on the outside in the radial direction, and a portion between an end surface on the outside in the radial direction of the retainer 13 of one roller 14 of adjoining rollers 14 in the radial direction and an end surface on the inside in the radial direction of the retainer 13 of another roller 14. As a result, the contact area of a sliding contact portion 32 is made smaller than in a case where an intermediate sliding member 27 is not provided.

The invention claimed is: 
     
       1. A pressing device for a toroidal continuously variable transmission, comprising:
 a cam plate having a first cam surface that is uneven in a circumferential direction on one side in an axial direction; 
 a disk having a toroidal curved surface with arc-shaped cross section on one side in the axial direction, and a second cam surface that is uneven in the circumferential direction on the other side in the axial direction and faces the first cam surface; 
 a retainer arranged between the first cam surface and the second cam surface and having rectangular shaped pockets arranged at a plurality of locations in the circumferential direction so that a center axis of the respective pockets is arranged in a radial direction; and 
 a plurality of rollers rotatably held inside the pockets with two or more rollers of the plurality of rollers arranged in a row in the radial direction of the retainer inside the respective pockets; 
 wherein 
 an intermediate sliding member provided separately from the respective rollers is arranged coaxially with the center axis of the respective rollers in at least one location of a portion between an end surface on an outside in the radial direction of the retainer of one roller of the two or more rollers arranged in the respective pockets that is located on an outermost side in the radial direction of the retainer and an inside surface of the respective pockets on the outside in the radial direction of the retainer, and a portion between an end surface on the outside in the radial direction of the retainer of one roller of adjoining rollers in the radial direction of the retainer of the two or more rollers and an end surface on an inside in the radial direction of the retainer of the other roller of the adjoining rollers; 
 sliding contact occurs between the intermediate sliding member and the inside surface of the respective pockets on the outside in the radial direction of the retainer, between the intermediate sliding member and the end surface on the outside in the radial direction of the retainer of the one roller located on the outermost side or the one roller of the adjoining rollers, between the intermediate sliding member and an end surface on the inside in the radial direction of the other roller, or a separate intermediate sliding member that is attached to each of the above surfaces; and 
 a contact area of a sliding contact portion between the intermediate sliding member and the above surfaces or the separate intermediate sliding member is smaller than a contact area of a sliding contact portion in a case where the intermediate sliding member is not provided and there is direct sliding contact between the end surface on the outside in the radial direction of the retainer of the one roller located on the outermost side and the inside surface on the outside in the radial direction of the retainer of the respective pockets, or between the end surface on the outside in the radial direction of the retainer of the one roller of the adjacent rollers and the end surface on the inside in the radial direction of the retainer of the other roller. 
 
     
     
       2. The pressing device for a toroidal continuously variable transmission according to  claim 1 , wherein the intermediate sliding member is attached to the end surface on the outside in the radial direction of the retainer of either of the rollers. 
     
     
       3. The pressing device for a toroidal continuously variable transmission according to  claim 2 , wherein
 the intermediate sliding member is attached to the end surface on the outside in the radial direction of the retainer of all the respective rollers, the intermediate sliding member is arranged coaxially with the center axis of the respective rollers in all locations of the portion between the end surface on the outside in the radial direction of the retainer of the one roller located on the outermost side in the radial direction of the retainer and the inside surface of the respective pockets on the outside in the radial direction of the retainer, and the portion between the end surface on the outside in the radial direction of the retainer of the one roller of the adjoining rollers and the end surface on the inside in the radial direction of the retainer of the other roller of the adjoining rollers. 
 
     
     
       4. The pressing device for a toroidal continuously variable transmission according to  claim 1 , wherein
 the intermediate sliding member has a tip end surface that comes in contact with the sliding contact portion, the tip end surface being configured with a spherical convex surface or a conical convex surface. 
 
     
     
       5. The pressing device for a toroidal continuously variable transmission according to  claim 1 , wherein
 a partial spherical or conical concave portion is provided in a portion that comes in sliding contact with the intermediate sliding member of the end surface of the respective rollers and/or the inside surfaces of the respective pockets of the retainer. 
 
     
     
       6. The pressing device for a toroidal continuously variable transmission according to  claim 1 , wherein
 at least the end surface on the outside in the radial direction of the retainer of the respective rollers comprises an R portion that connects the end surface with a rolling surface of the respective rollers, and an attaching portion provided in a center portion in the radial direction of the end surface for attaching the intermediate sliding member; wherein a surface that constitutes the end surface that is located on an outermost side in the radial direction of the retainer of the end surface is constructed by a flat surface that extends in a direction orthogonal to the center axis of the respective rollers. 
 
     
     
       7. The pressing device for toroidal continuously variable transmission according to  claim 6 , wherein
 the attaching portion is configured by a concave portion that is provided on the end surface and the end surface corresponds to the surface located on the outermost side. 
 
     
     
       8. The pressing device for toroidal continuously variable transmission according to  claim 6 , wherein
 the attaching portion is configured by a convex portion provided on the end surface, and the surface located on the outermost side is constructed by a tip end surface of the convex portion. 
 
     
     
       9. The pressing device for toroidal continuously variable transmission according to  claim 1 , wherein
 the intermediate sliding member is made of material having hardness that is lower than hardness of a material constituting the respective rollers.